Testosterone supplements, also called testosterone boosters, are typically all-natural supplements used to increase levels of the testosterone hormone in an effort to increase muscle mass quickly. Testosterone is the primary hormone responsible for muscle growth, and the body tends to release less of this hormone as you get older. Testosterone supplements are generally not recommended for use by anyone under the age of 25 because that group’s testosterone levels are already at optimum levels for muscle growth.
Testosterone supplements, such as Tribulus terrestris, have a long history that dates back hundreds of years. Although not first used as a way to increase muscle mass, tribulus was used for medicinal purposes in China, India and Greece. It was used to boost libido in both men and women, as well as a treatment for speeding up recovery from long-term illnesses. Testosterone supplements made their way to the West when Bulgarian Olympic athletes, who dominated weight lifting competitions at the time, began to attribute their strength to tribulus and similar testosterone-boosting plants and herbs. Today, numerous studies have shown that testosterone-boosting products have little or no effect on sports performance, according to a published report at New York University’s Langone Medical Center website.
The two main types of all-natural testosterone supplements contain either Tribulus terrestris or zinc monomethionine aspartate (ZMA). Tribulus is a vine plant that grows in moderate to tropical climates, such as those found in the United States and Mexico. By stimulating the anterior pituitary gland, this plant can help to increase production of testosterone in the body. ZMA, on the other hand, increases the body’s testosterone production by boosting anabolic hormone levels. These two main ingredients can be found in just about any testosterone booster on the market.
Peter Van Mol of BodyBuilding.com recommends taking ZMA or Tribulus terrestris at the correct dosage for optimal muscle gains. He encourages taking the manufacturer’s recommended amount of ZMA in cycles, beginning with the last three days of your weekly lifting regimen and continuing this cycle for two to three weeks thereafter. For those taking Tribulus testosterone boosters, he recommends taking 1,250 to 2,000 mg each day, depending upon your weight and whether it is a workout day. As with any weight lifting supplement, however, it’s best to follow the manufacturer’s recommended dosage guidelines found on each individual product’s packaging.
When it comes to side effects, studies have shown that testosterone supplements generally produce no serious side effects when following the manufacturer's recommended dosage guidelines. The Langone Medical Center notes that Tribulus terrestris has been shown to be toxic in sheep, although there have been no such reports of it being toxic to humans. However, women who are pregnant or nursing should not use any product that may affect hormone levels in any way unless otherwise prescribed by their doctor.
A 2004 study published in the "Journal of the International Society of Sports Nutrition" examined whether ZMA—a popular active ingredient found in testosterone supplements—actually helped resistance-trained males build muscle and strength. After eight weeks, the study concluded that “ZMA supplementation during training does not appear to enhance training adaptations in resistance-trained populations.” The study participants—42 of them in all—showed little or no difference in strength between the control group and the ZMA supplement group.